UN Secretary General Ban Ki-moon has renewed his support for substantive peace negotiations between the Afghan government and Taliban on Sunday. \"We have been discussing this matter with Afghanistan\'s leaders. We have been supporting and trying to facilitate this dialogue,\" Ban said in remarks, adding that the dialogue process should lead to permanent peace and security as Afghans had suffered a great deal due to violence. Referring to his meeting with Prime Minister of Pakistan Nawaz Sharif and Afghan President Hamid Karzai in August, Ban said that he has been urging the two leaders to strengthen bilateral ties so they could address all security issues, including talks with the Taliban. He also praised the Pakistani government for hosting over 1.6 million Afghan refugees despite its limited economic resources. He added: \"I am also grateful that the Pakistani government has recently extended their (Afghan refugees) right of stay beyond June this year. Even though there might have been very difficult circumstances, I hope the Pakistani government will continue to provide necessary humanitarian assistance to the Afghan refugees.\" \"I am concerned whether one can ensure that the use of drones can guarantee the legitimate target, whether targeted persons are combatants or legitimate targets, according to relevant laws and regulations,\" he continued. He expressed hope that the countries using the drone technology would make sure there were no casualties on the part of the civilian population.